arch/ia64/ia32/binfmt_elf32.c - kernel/msm - Gitiles

 /*
  * IA-32 ELF support.
  *
  * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
  * Copyright (C) 2001 Hewlett-Packard Co
  *	David Mosberger-Tang <davidm@hpl.hp.com>
  *
  * 06/16/00	A. Mallick	initialize csd/ssd/tssd/cflg for ia32_load_state
  * 04/13/01	D. Mosberger	dropped saving tssd in ar.k1---it's not needed
  * 09/14/01	D. Mosberger	fixed memory management for gdt/tss page
  */

 #include <linux/types.h>
 #include <linux/mm.h>
 #include <linux/security.h>

 #include <asm/param.h>
 #include <asm/signal.h>

 #include "ia32priv.h"
 #include "elfcore32.h"

 /* Override some function names */
 #undef start_thread
 #define start_thread			ia32_start_thread
 #define elf_format			elf32_format
 #define init_elf_binfmt			init_elf32_binfmt
 #define exit_elf_binfmt			exit_elf32_binfmt

 #undef CLOCKS_PER_SEC
 #define CLOCKS_PER_SEC	IA32_CLOCKS_PER_SEC

 extern void ia64_elf32_init (struct pt_regs *regs);

 static void elf32_set_personality (void);

 static unsigned long __attribute ((unused))
 randomize_stack_top(unsigned long stack_top);

 #define setup_arg_pages(bprm,tos,exec)		ia32_setup_arg_pages(bprm,exec)
 #define elf_map				elf32_map

 #undef SET_PERSONALITY
 #define SET_PERSONALITY(ex)	elf32_set_personality()

 #define elf_read_implies_exec(ex, have_pt_gnu_stack)	(!(have_pt_gnu_stack))

 /* Ugly but avoids duplication */
 #include "../../../fs/binfmt_elf.c"

 extern struct page *ia32_shared_page[];
 extern unsigned long *ia32_gdt;
 extern struct page *ia32_gate_page;

 int
 ia32_install_shared_page (struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	vmf->page = ia32_shared_page[smp_processor_id()];
 	get_page(vmf->page);
 	return 0;
 }

 int
 ia32_install_gate_page (struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	vmf->page = ia32_gate_page;
 	get_page(vmf->page);
 	return 0;
 }


 static struct vm_operations_struct ia32_shared_page_vm_ops = {
 	.fault = ia32_install_shared_page
 };

 static struct vm_operations_struct ia32_gate_page_vm_ops = {
 	.fault = ia32_install_gate_page
 };

 void
 ia64_elf32_init (struct pt_regs *regs)
 {
 	struct vm_area_struct *vma;

 	/*
 	 * Map GDT below 4GB, where the processor can find it.  We need to map
 	 * it with privilege level 3 because the IVE uses non-privileged accesses to these
 	 * tables.  IA-32 segmentation is used to protect against IA-32 accesses to them.
 	 */
 	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 	if (vma) {
 		vma->vm_mm = current->mm;
 		vma->vm_start = IA32_GDT_OFFSET;
 		vma->vm_end = vma->vm_start + PAGE_SIZE;
 		vma->vm_page_prot = PAGE_SHARED;
 		vma->vm_flags = VM_READ|VM_MAYREAD|VM_RESERVED;
 		vma->vm_ops = &ia32_shared_page_vm_ops;
 		down_write(&current->mm->mmap_sem);
 		{
 			if (insert_vm_struct(current->mm, vma)) {
 				kmem_cache_free(vm_area_cachep, vma);
 				up_write(&current->mm->mmap_sem);
 				BUG();
 			}
 		}
 		up_write(&current->mm->mmap_sem);
 	}

 	/*
 	 * When user stack is not executable, push sigreturn code to stack makes
 	 * segmentation fault raised when returning to kernel. So now sigreturn
 	 * code is locked in specific gate page, which is pointed by pretcode
 	 * when setup_frame_ia32
 	 */
 	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 	if (vma) {
 		vma->vm_mm = current->mm;
 		vma->vm_start = IA32_GATE_OFFSET;
 		vma->vm_end = vma->vm_start + PAGE_SIZE;
 		vma->vm_page_prot = PAGE_COPY_EXEC;
 		vma->vm_flags = VM_READ | VM_MAYREAD | VM_EXEC
 				| VM_MAYEXEC | VM_RESERVED;
 		vma->vm_ops = &ia32_gate_page_vm_ops;
 		down_write(&current->mm->mmap_sem);
 		{
 			if (insert_vm_struct(current->mm, vma)) {
 				kmem_cache_free(vm_area_cachep, vma);
 				up_write(&current->mm->mmap_sem);
 				BUG();
 			}
 		}
 		up_write(&current->mm->mmap_sem);
 	}

 	/*
 	 * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
 	 * until a task modifies them via modify_ldt().
 	 */
 	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
 	if (vma) {
 		vma->vm_mm = current->mm;
 		vma->vm_start = IA32_LDT_OFFSET;
 		vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 		vma->vm_page_prot = PAGE_SHARED;
 		vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 		down_write(&current->mm->mmap_sem);
 		{
 			if (insert_vm_struct(current->mm, vma)) {
 				kmem_cache_free(vm_area_cachep, vma);
 				up_write(&current->mm->mmap_sem);
 				BUG();
 			}
 		}
 		up_write(&current->mm->mmap_sem);
 	}

 	ia64_psr(regs)->ac = 0;		/* turn off alignment checking */
 	regs->loadrs = 0;
 	/*
 	 *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 	 *  one we'll set it to 0 and initialize all the other registers just to make
 	 *  things more deterministic, ala the i386 implementation.
 	 */
 	regs->r8 = 0;	/* %eax */
 	regs->r11 = 0;	/* %ebx */
 	regs->r9 = 0;	/* %ecx */
 	regs->r10 = 0;	/* %edx */
 	regs->r13 = 0;	/* %ebp */
 	regs->r14 = 0;	/* %esi */
 	regs->r15 = 0;	/* %edi */

 	current->thread.eflag = IA32_EFLAG;
 	current->thread.fsr = IA32_FSR_DEFAULT;
 	current->thread.fcr = IA32_FCR_DEFAULT;
 	current->thread.fir = 0;
 	current->thread.fdr = 0;

 	/*
 	 * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 	 * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 	 * architecture manual. Also note that the only fields that are not ignored are
 	 * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 	 */
 	regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 							    0, 0, 0, 1, 0, 0, 0));
 	/* Setup the segment selectors */
 	regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 	regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */

 	ia32_load_segment_descriptors(current);
 	ia32_load_state(current);
 }

 /*
  * Undo the override of setup_arg_pages() without this ia32_setup_arg_pages()
  * will suffer infinite self recursion.
  */
 #undef setup_arg_pages

 int
 ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
 {
 	int ret;

 	ret = setup_arg_pages(bprm, IA32_STACK_TOP, executable_stack);
 	if (!ret) {
 		/*
 		 * Can't do it in ia64_elf32_init(). Needs to be done before
 		 * calls to elf32_map()
 		 */
 		current->thread.ppl = ia32_init_pp_list();
 	}

 	return ret;
 }

 static void
 elf32_set_personality (void)
 {
 	set_personality(PER_LINUX32);
 	current->thread.map_base  = IA32_PAGE_OFFSET/3;
 }

 static unsigned long
 elf32_map(struct file *filep, unsigned long addr, struct elf_phdr *eppnt,
 		int prot, int type, unsigned long unused)
 {
 	unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;

 	return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 			    eppnt->p_offset - pgoff);
 }

 #define cpu_uses_ia32el()	(local_cpu_data->family > 0x1f)

 static int __init check_elf32_binfmt(void)
 {
 	if (cpu_uses_ia32el()) {
 		printk("Please use IA-32 EL for executing IA-32 binaries\n");
 		unregister_binfmt(&elf_format);
 	}
 	return 0;
 }

 module_init(check_elf32_binfmt)
	/*
	* IA-32 ELF support.
	*
	* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
	* Copyright (C) 2001 Hewlett-Packard Co
	* David Mosberger-Tang <davidm@hpl.hp.com>
	*
	* 06/16/00 A. Mallick initialize csd/ssd/tssd/cflg for ia32_load_state
	* 04/13/01 D. Mosberger dropped saving tssd in ar.k1---it's not needed
	* 09/14/01 D. Mosberger fixed memory management for gdt/tss page
	*/

	#include <linux/types.h>
	#include <linux/mm.h>
	#include <linux/security.h>

	#include <asm/param.h>
	#include <asm/signal.h>

	#include "ia32priv.h"
	#include "elfcore32.h"

	/* Override some function names */
	#undef start_thread
	#define start_thread ia32_start_thread
	#define elf_format elf32_format
	#define init_elf_binfmt init_elf32_binfmt
	#define exit_elf_binfmt exit_elf32_binfmt

	#undef CLOCKS_PER_SEC
	#define CLOCKS_PER_SEC IA32_CLOCKS_PER_SEC

	extern void ia64_elf32_init (struct pt_regs *regs);

	static void elf32_set_personality (void);

	static unsigned long __attribute ((unused))
	randomize_stack_top(unsigned long stack_top);

	#define setup_arg_pages(bprm,tos,exec) ia32_setup_arg_pages(bprm,exec)
	#define elf_map elf32_map

	#undef SET_PERSONALITY
	#define SET_PERSONALITY(ex) elf32_set_personality()

	#define elf_read_implies_exec(ex, have_pt_gnu_stack) (!(have_pt_gnu_stack))

	/* Ugly but avoids duplication */
	#include "../../../fs/binfmt_elf.c"

	extern struct page *ia32_shared_page[];
	extern unsigned long *ia32_gdt;
	extern struct page *ia32_gate_page;

	int
	ia32_install_shared_page (struct vm_area_struct vma, struct vm_fault vmf)
	{
	vmf->page = ia32_shared_page[smp_processor_id()];
	get_page(vmf->page);
	return 0;
	}

	int
	ia32_install_gate_page (struct vm_area_struct vma, struct vm_fault vmf)
	{
	vmf->page = ia32_gate_page;
	get_page(vmf->page);
	return 0;
	}


	static struct vm_operations_struct ia32_shared_page_vm_ops = {
	.fault = ia32_install_shared_page
	};

	static struct vm_operations_struct ia32_gate_page_vm_ops = {
	.fault = ia32_install_gate_page
	};

	void
	ia64_elf32_init (struct pt_regs *regs)
	{
	struct vm_area_struct *vma;

	/*
	* Map GDT below 4GB, where the processor can find it. We need to map
	* it with privilege level 3 because the IVE uses non-privileged accesses to these
	* tables. IA-32 segmentation is used to protect against IA-32 accesses to them.
	*/
	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
	if (vma) {
	vma->vm_mm = current->mm;
	vma->vm_start = IA32_GDT_OFFSET;
	vma->vm_end = vma->vm_start + PAGE_SIZE;
	vma->vm_page_prot = PAGE_SHARED;
	vma->vm_flags = VM_READ\|VM_MAYREAD\|VM_RESERVED;
	vma->vm_ops = &ia32_shared_page_vm_ops;
	down_write(&current->mm->mmap_sem);
	{
	if (insert_vm_struct(current->mm, vma)) {
	kmem_cache_free(vm_area_cachep, vma);
	up_write(&current->mm->mmap_sem);
	BUG();
	}
	}
	up_write(&current->mm->mmap_sem);
	}

	/*
	* When user stack is not executable, push sigreturn code to stack makes
	* segmentation fault raised when returning to kernel. So now sigreturn
	* code is locked in specific gate page, which is pointed by pretcode
	* when setup_frame_ia32
	*/
	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
	if (vma) {
	vma->vm_mm = current->mm;
	vma->vm_start = IA32_GATE_OFFSET;
	vma->vm_end = vma->vm_start + PAGE_SIZE;
	vma->vm_page_prot = PAGE_COPY_EXEC;
	vma->vm_flags = VM_READ \| VM_MAYREAD \| VM_EXEC
	\| VM_MAYEXEC \| VM_RESERVED;
	vma->vm_ops = &ia32_gate_page_vm_ops;
	down_write(&current->mm->mmap_sem);
	{
	if (insert_vm_struct(current->mm, vma)) {
	kmem_cache_free(vm_area_cachep, vma);
	up_write(&current->mm->mmap_sem);
	BUG();
	}
	}
	up_write(&current->mm->mmap_sem);
	}

	/*
	* Install LDT as anonymous memory. This gives us all-zero segment descriptors
	* until a task modifies them via modify_ldt().
	*/
	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
	if (vma) {
	vma->vm_mm = current->mm;
	vma->vm_start = IA32_LDT_OFFSET;
	vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
	vma->vm_page_prot = PAGE_SHARED;
	vma->vm_flags = VM_READ\|VM_WRITE\|VM_MAYREAD\|VM_MAYWRITE;
	down_write(&current->mm->mmap_sem);
	{
	if (insert_vm_struct(current->mm, vma)) {
	kmem_cache_free(vm_area_cachep, vma);
	up_write(&current->mm->mmap_sem);
	BUG();
	}
	}
	up_write(&current->mm->mmap_sem);
	}

	ia64_psr(regs)->ac = 0; /* turn off alignment checking */
	regs->loadrs = 0;
	/*
	* According to the ABI %edx points to an `atexit' handler. Since we don't have
	* one we'll set it to 0 and initialize all the other registers just to make
	* things more deterministic, ala the i386 implementation.
	*/
	regs->r8 = 0; /* %eax */
	regs->r11 = 0; /* %ebx */
	regs->r9 = 0; /* %ecx */
	regs->r10 = 0; /* %edx */
	regs->r13 = 0; /* %ebp */
	regs->r14 = 0; /* %esi */
	regs->r15 = 0; /* %edi */

	current->thread.eflag = IA32_EFLAG;
	current->thread.fsr = IA32_FSR_DEFAULT;
	current->thread.fcr = IA32_FCR_DEFAULT;
	current->thread.fir = 0;
	current->thread.fdr = 0;

	/*
	* Setup GDTD. Note: GDTD is the descrambled version of the pseudo-descriptor
	* format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
	* architecture manual. Also note that the only fields that are not ignored are
	* `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
	*/
	regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
	0, 0, 0, 1, 0, 0, 0));
	/* Setup the segment selectors */
	regs->r16 = (__USER_DS << 16) \| __USER_DS; /* ES == DS, GS, FS are zero */
	regs->r17 = (__USER_DS << 16) \| __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */

	ia32_load_segment_descriptors(current);
	ia32_load_state(current);
	}

	/*
	* Undo the override of setup_arg_pages() without this ia32_setup_arg_pages()
	* will suffer infinite self recursion.
	*/
	#undef setup_arg_pages

	int
	ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
	{
	int ret;

	ret = setup_arg_pages(bprm, IA32_STACK_TOP, executable_stack);
	if (!ret) {
	/*
	* Can't do it in ia64_elf32_init(). Needs to be done before
	* calls to elf32_map()
	*/
	current->thread.ppl = ia32_init_pp_list();
	}

	return ret;
	}

	static void
	elf32_set_personality (void)
	{
	set_personality(PER_LINUX32);
	current->thread.map_base = IA32_PAGE_OFFSET/3;
	}

	static unsigned long
	elf32_map(struct file filep, unsigned long addr, struct elf_phdr eppnt,
	int prot, int type, unsigned long unused)
	{
	unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;

	return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
	eppnt->p_offset - pgoff);
	}

	#define cpu_uses_ia32el() (local_cpu_data->family > 0x1f)

	static int __init check_elf32_binfmt(void)
	{
	if (cpu_uses_ia32el()) {
	printk("Please use IA-32 EL for executing IA-32 binaries\n");
	unregister_binfmt(&elf_format);
	}
	return 0;
	}

	module_init(check_elf32_binfmt)